Patient supporting tables are used extensively in many medical related applications such as surgery, examination and therapy. They are also used for patient support in radiographic systems, such as x-ray systems. More particularly, a typical x-ray system includes an x-ray table having a top upon which a patient is positioned. The table top is typically moveable laterally and longitudinally for ease of patient positioning. An x-ray source is generally positioned above the table top and an x-ray film cassette or other image recorder is positioned below the table top.
The x-ray table must fulfil a number of often conflicting design requirements. For example, the underside surface of the table top must be free of obstructions so that the table top can be moveable relative to the x-ray apparatus to allow for patient positioning. The table top also must be thin so that the x-ray film may be placed as close to the patient as possible The table top must also be constructed of a material which is relatively transparent to x-rays so that a high quality image may be obtained. Also, the table must be able to support a person weighing up to 400 pounds.
In order to accommodate these conflicting design requirements, known x-ray table tops have been constructed of a thin panel of a paper base resinous material. The resinous panel is sufficiently thin (3/8" or less in thickness) to provide minimal attenuation of x-rays and to allow the x-ray film to be positioned close to the patient. The panel is suspended only at its ends by a pair of longitudinally extending frame members so that unobstructed movement of the top may be obtained. The longitudinally extending frame members grip the panel so that the thin panel can support a human being without collapsing. X-ray tables as described above are illustrated in U.S. Pat. Nos. 3,967,126 to Otto, Jr., 4,208,586 to Craig et al., and 4,365,345 to Craig et al.
In order to adequately support the thin panel, the frame members of the above described tables have gripped the panel on the top surface and on the bottom surface thereof. Accordingly, the longitudinal frame members included panel gripping surfaces above and below the panel. The gripping surface above the panel produced a lip in the frame members, rising above the top surface of the panel and extending longitudinally along the entire length of the panel. As a result of this longitudinal lip it has been difficult to transfer a patient directly from a stretcher or other table onto the x-ray table. This lip also made it difficult to transfer a patient from the x-ray table back to a stretcher.
The lip also presents problems for positioning the x-ray source and the x-ray film during various radiological procedures. For example when obtaining a lateral spine x-ray of a patient lying on his back on the table top, the x-ray source must be positioned to emit x-rays parallel to the table top and centered about 1/2" above the table top in order to center the x-rays on the spine. In this procedure, the lip interferes with passage of the x-rays. Also, when obtaining an x-ray of an extremity such as a lower leg, the x-ray film is typically positioned on the table top, with the extremity lying on the film. In this procedure, the lip interferes with the positioning of the x-ray film. Unfortunately, to the best of Applicant's knowledge, the lip on the table top has heretofore been essential because the longitudinal frame members had to grip the top and bottom surfaces of the thin panel.